The overall goal of the proposed CPRU is the development of strategies for the prevention of colorectal cancer. To accomplish that goal, a multi- disciplinary groups of scientists is collaborating on a group of projects using shared resources. The studies revolve around understanding better the factors which increase risk of development of adenomatous polyps and the undertaking of a feasibility study on the prevention of recurrence of these lesions. There are 4 specific projects: a) a case-control study of the role of familial and environmental factors in the occurrence of adenomatous polyps; b) a study to establish the feasibility of major dietary intervention (specifically increasing vegetable and fruit intake) in the recurrence of polyps; c) studies seeking to improve self-report dietary methods for etiologic and intervention studies; d) feeding studies to dietary methods for etiologic and intervention studies; d) feeding studies to test objective markers of diet exposure, specifically exposure to vegetables and fruit; There are 5 core support units: Dietary; Laboratory; Clinical; Statistical and DAta management; and Survey. The program is integrated at a number of levels - thematic, organizational, data-sharing, resource-sharing, and intended future cross-disciplinary studies. It is based on the extensive prior experience of the collaborators in the relevant areas, relates strongly to other existing research and emphasizes combined and complementary skills in the intellectual effort. The program is a collaborative arrangement among the personnel, and using the resources, of 3 divisions of the School of Public Health, 2 departments of the Medical School, and 1 department of the School of Agriculture of the University of Minnesota.